(WASHINGTON) —The top Democrat on a House oversight committee says documents he’s reviewed suggest that former National Security Adviser Michael Flynn lied to federal security clearance investigators about the source of payments Flynn received from a Russian state-sponsored television network.

Rep. Elijah Cummings of Maryland says Flynn told the investigators during an early 2016 security clearance review that a trip to Moscow was “funded by U.S. companies.” Cummings says the actual source of the funds was “the Russian media propaganda arm, RT.”

Cummings made the statements in a letter to Rep. Jason Chaffetz, the Utah Republican and chairman of the House oversight committee. Cummings’ letter came the same day Flynn declined to provide documents to the Senate Intelligence Committee, citing his Fifth Amendment protection from self-incrimination.